I've taken 8 pregnancy tests in the past two weeks. Different brands & from different stores. None have registered a control line..... no lines at all. I've taken many tests in the past and have NEVER had this problem. I'm using first morning urine?

Interesting. I think a talk with your pharmacist is in order. Either you have been using a bad lot or you are doing something wrong.
Blood test for HCG. Did you have unprotected sex since your last period? Did you miss a period? If the answer to both is yes, see your doctor for a blood to examine HCG level.
Pregnancy. Do you think you are pregnant? Are missing periods, were you regular in the past? Do you have the brands? Did you check the expiration date? Some tests indicate a flashing symbol in the window before the result. +- If you think that you are pregnant see an OBGYN.